List of top Physics Questions

The reddish appearance of the sun at sunrise and sunset is due to

The amplitude of a damped oscillator decreases to $0.9$ times its original magnitude is $5\, s$. In another $10\, s$ it will decrease to a times its original magnitude, where $\alpha$ equals

The image of an illuminated square is obtained on a screen with the help of a converging lens. The distance of the square from the lens is $40\, cm$. The area of the image is $9$ times that of the square. The focal length of the lens is :

Two blocks of masses $m$ and $M$ are connected by means of a metal wire of cross-sectional area $A$ passing over a frictionless fixed pulley as shown in the figure. The system is then released. If $M \,= \,2 m$, then the stress produced in the wire is:

A vessel contains a mixture of $1$ mole of oxygen and two moles of nitrogen at $300 \,K$. The ratio of the rotational kinetic energy per $ O_{2} $ molecule to that per $ N_{2} $ molecule is

The velocity of a projectile at the initial point A is (2i+3j) m/s. Its velocity (in m/s) at point B is

A rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a massless string tied to point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is

Two pith balls carrying equal charges are suspended from a common point by strings of equal length, the equilibrium separation between them is 7. Now the strings are rigidly clamped at half the height. The equilibrium separation between the balls now become

The amount of heat energy required to raise the temperature of 1 g of Helium at NTP, from $T_1K$ to $T_2K$ is

A stone falls freely under gravity. It covers distances $h_1, \, h_2 $ and $h_3$ in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between $h_1 , \,h_2 $ and $h_3$ is

A wave travelling in the +ve x-direction having displacement along y-direction as 1 m, wavelength 2π in and frequency of $\frac1{π}$Hz is represented by

If we study the vibration of a pipe open at both ends, then the following statement is not true

The upper half of an inclined plane of inclination θ is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between the block and lower half of the plane is given by

In Young's double slit experiment, the slits are 2 mm apart and are illuminated by photons of two wavelengths, $λ_1$ =12000 Å and $λ_2$= 10000 Å. At what minimum distance from the common central bright fringe on the screen 2 m from the slit will a bright fringe from one interference patter coincide with a bright fringe from the other?

A parallel beam of fast moving electrons is incident normally on a narrow shit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct?

In the given (V-T) diagram, what is the relation between pressures $P_1$ and $P_2$ ?

A body of mass w taken from the earth's surface to the height equal to twice the radius (R) of the earth. The change in potential energy of body will be

A current loop in a magnetic field

A wire loop is rotated in a magnetic field. The frequency of change of direction of the induced

The molar specific heats of an ideal gas at constant pressure and volume are denoted by $C_p$ and $C_V$ respectively. If $ γ = \frac{C_P}{C_v}$ and R is the universal gas constant, then $C_V$ is equal to

A, B and C are three points in a uniform electric field. The electric potential is

When a proton is released from rest in a room, it starts with an initial acceleration $a_0$ towards west. When it is projected towards north with a speed $v_0$ it moves with an initial acceleration 3$a_0$ toward west. The electric and magnetic fields in the room

In a common emitter (CE) amplifier having a voltage gain G, the transistor used has transconductance 0.03 mho and current gain 25. If the above transistor is replaced with another one with transconductance 0.02 mho and current gain 20, the voltage gain will be

Infinite number of bodies, each of mass 2 kg are situated on x-axis at distance 1 m, 2 m, 4 m, 8 m respectively, from the origin. The resulting gravitational potential due to this system at the origin will be

Three blocks with masses m, 2m and 3m are connected by strings, as shown in the figure. After an upward force F is applied on block m, the masses move upward at constant speed v. What is the net force on the block of mass 2 m? (g is the acceleration due to gravity)